Polisher



J. G. PARTLow 1,954,489

POLISHER Filed March 30, 1931 3 Sheets-Sheet l Fl I l 3 9/ Y 4o April1o, 1934.

ATTORNEYS.

April l0, 1934. J, G. PARTLow POLISHER Filed March 30, 1951 3Sheets-Sheet 2 NVENTOR. @im G. Par-L l ow *will A TTORNEYS.

AprilY 10, 1934. J. G. PARTLow POLISHER Filed March 30, 1931 5Sheets-Sheet 3 INVENTOR. dbh" G, Pay-HOW.

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Patented Apr. 10, 1934 POLISHER t John G. Partlow, Grand Ledge, Mich.,assignor of one-half to Roy G. Micheli, Detroit, Mich.

Application March 30, 1931, Serial No. 526,359

7 Claims.

This invention relates to a polisher of the reciprocating type.

In the polishing and Wet sanding field, and particularly in thepolishing of the ilnish on 5 vehicle bodies, it has long been a desireto obtain a polishing machine that is light of Weight, that will notscratch the nish, and which will have a minimum vibration. It is theobject of this invention to produce a pneumatic polishing l machineconsisting of a minimum of parts which is readily assembled, light ofweight, substantially free from undesirable vibration, and Which willnot scratch the iinish.

Since, from the very nature of the Work for l which such a machine isconstructed, it must operate in the presence of dust and grit, obviouslyif any dust or grit gets between the parts having a relative slidingengagement, the Wear will be excessive and soon render the machineinoperative. Hence, it is a further object of this invention to producea pneumatic polishing machine in Which a uid blast is utilized toprevent dust, grit and other foreign matter from getting between thesliding parts of the machine.

It is a further object of this invention to produce a novel means forsecuring the Web of abrasive to the reciprocating pad support.

In the drawings: Fig. 1 is a longitudinal section through the Aassembled polishing machine.

Fig. 2 is a section along the line 2 2 of Fig. 1.

Fig. 3 is a detail showing the position of the valve relative to oneposition of the piston.

Fig. 5 is a detail of thevalve slide.

Fig. 6 is a detail of the valve guide portion of the cylinder.

Fig. 'l is a side elevation of the motor.

Fig. Sis a section along the line 8*-8 of Fig. '7.

Fig. 9 is an end elevation of the machine. Fig. 10 shows a plan View ofthe polisher having a modified form of Water and air control.

Fig. 11 is a fragmentary combination sectional and elevational view ofthe polisher shown in Fig. 10 with the air and Water turned off.

Figs. 12 and 13 are views similar to Figs. 10 and l1 showing the Waterand air turned on.

Referring more particularly tothe drawings, it will be seen that thispolisher is pneumatically operated and of the'reciprocating type. Sincethis polisher may be used in various operations such as polishing Ducoor on Wet sanding, a suitable reciprocating work supporting plate 1 isused. This plate is arranged to have removlli Wlillilllllmlilllllmimmmw\.mitmiliariwt.

ably secured thereto, in any suitable manner, a pad 2. As shown, the padsecuring means comprises a thin plate 3 which has glued or otherwisesecured thereto the pad 2 which is preferably Vof any resilient materialsuch as sponge rubber. The plate 3 is secured in any suitable Way to theplate 1. The pad 2, When the machine is used for sanding, is arranged tobe faced with one or more webs of sand paper 4 or any other abrasivematerial..

. IThe plate 1 is provided at each end with a transverse groove 5. Arelatively stiff spring 6 has one end xed to the plate 1 as at 'I andthe other end provided With a knuckle 8 which receives the pintle 9. Thepintle 9 has mounted 'I0 thereon the U-shaped member 1U which hasrotatably mounted between the ends thereof the knurled roller 11. Asshown in Fig. 7 a plurality of plies of abrasive material 4 are mountedupon the Work supporting pad, the ends of which are held tightly in thegroove 5 by the knurled roller 11 and associated spring 6. The spring 6,in order to hold several plies of abrasive upon the pad at one time,must necessarily be relatively stiff. .The knurled roller 11 permits theuse of a relatively stiff spring because of the fact that it assists theoperator materially in overcoming the tension of the spring when thefastening means are shifted from the released position shown in thedotted lines (Fig. '7) to the locked position shown in the full lines byits rolling action over the inclined face 12 of the support plate 1.

The reciprocatory plate l is arranged to be directly fixed to the piston13 which operates in the cylinderl4. The cylinder 14 is provided at eachend With a threaded plug 15 and at the top and bottom with the slots 16and 17 respectively. The cylinder 14 is provided with a pair oflongitudinal ribs 18 lwhich slidably engage the upstanding rib 19 of theplate 1 to guide the same in its reciprocation. The ribs 18 are providedwith longitudinal grooves which receive the lubricating felt 20. Theplate 1 is provided with the square boss 21 which has a round opening 22cen- 100 trally thereof. The piston 13 is provided withr similar squareopenings 23 and 24. The boss 21 of the plate 1 is arranged to have avery snug fit with the opening 23 in the cylinder 14 and held in thisposition by means of the threaded stud 105 25. The threaded end of thestud 25 is threaded into a hardened steel plug 26 arranged to have asnug fit in the opening 24 of the cylinder 14. This plug 26 has anupstanding stud 27 which serves to reciprocate the valve slide. Inopera- 110 tion the main working thrust will be borne by the boss 21 andthe plug 26 and owing to their snug, square intert with the openings 23and 24 will eifectively resist any shearing strains of operation.

The upper surface 28 of the cylinder is flat and serves as a guide andsliding surface for the reciprocating valve 29. The valve 29 is of theflat plate type and has a lap fit with the guide surface 28. This lap tis perfect at all times because the valve, as it reciprocates,continually wears or laps itself into a more perfect contact with theguide surface 28.

The valve 29 is provided with the intake ports 30 and 31 which extendthrough the valve. The underside of the valve is provided at oppositeends with the recesses 32 and 33 respectively which cooperate with thevalve slide surf ace28 to form a chamber. The central portion 34 issomewhat narrower as at 35 than the end portions to permit passage ofthe air through the valve housing. The central portion 34 of the valveis provided with the recess 100 for the valve insert 101. The valveinsert has an opening 36 for engagement with the stud 27. The opening 36can be made any size desired to properly coordinate the valve therebychange the length of the piston stroke.

t" In other words, the operator can have at hand a plurality of valveinserts 101 having various` proaches that of the piston and Vice versa.

valve 29.

structure with the piston structure. In other words, by altering therelative dimensions of the recess 36 and stud 27, lost play between therecess 36 and the stud 27 is increased or decreased to As shown, thevalve 33 has a stroke of a suitable distance to cover the ports which inthis instance is approximately of an inch whereas the piston stroke isslightly longer than the travel of the Hence, a small clearance as at 37(Fig. 3), is allowed between the sides of the recess 36 and the stud 27.The smaller this clearance 3 7 is made the nearer the stroke of thevalve ap- The stroke of the valve can be increased or decreased wheneverit is desired by replacing the valve insert in the recess 100 of thevalvel with a different valve insert in which the opening 36 is of theproper size or diameter to get` the desired stroke.

sized openings and whenever he desires to change the valve stroke he canmerely remove the insert then in the valve recess 100 and replace thesame with another valve insert having an appropriately sized opening 36.

The valve guide surface 28 of the cylinder member has the intake ports38 and 39 which' communicate with the inside of the cylinder 13.

The valve guide surface likewise has the openings 40 and 41 extendingfrom the guide surface 32 substantially half way through 'the valveguide where each communicate with the transverse openings 42 and 43respectively. The openings 42 and 43 extend longitudinally as at 44 and45` respectively (Fig. 6) where they again communicate with thetransverse openings 46 and`47 which in turn communicate with the intakeopenings 38 and 39. The valve guide surface has bored `therethrough thelateral openings 50 and 51 which communicate with the vertical openings52 and 53 in the valve guide surface. The transverse openings 50 and 51communicate withvthe the valve guide surface 28 and is also arranged tobe held against the guide surface by air pressure. Therefore, the valveis provided with a suitable housing 55 which cooperates with the guidesurface to form the air chamber 56. The central portion 34 of the valveclears the valve housing as at 57. Compressed fluid, preferably air, isconducted through the air chamber through the air pressure line 58 whichis attached to the valve housing by any suitable means such as thethreads 59. The air line communicates with a suitable port 60 which inturn communicates with the chamber 56 as' at'61. The port 60 iscontrolled by a spring pressed check valve 62 which is arranged to setagainst the valve seat 63 and is backed up by the coil spring 64. Thecheck valve 62 is arranged to be operated by a plunger 65 which isslidably mounted in the opening 66 in the valve housing 55. The valvehousing 55 has pivotally mounted thereon as at 67 the cam 68. The camhas a downwardly projecting finger 69 which is engaged on either side bythe thumb slide 70. As the thumb slide 70 is pushed back and forthalternately, the cam action ofthe cam 68 against the end of the plunger65 opens and closes the check valve 62 to in turn start and stop thepneumatic motor.

The motor is arranged to be enclosed by a casing 71', which inconjunction with the slide 1, completely encloses thev motor. The casing71 is secured to the motor at each end adjacent the bottom by the screws72. Since it is veryneces.- sary to prevent the accessof Vgrit and dusttothe slide surfaces', it is proposed to shield the guide surfacesagainst dustv and grit by means of a fluid blast. Any suitable means maybe utilized for providing this protective fluid blast. As here shown, itisgproposed as' a matter of convenience to use the exhaustA blast fromthe exhaust ports 50 and 51. To this end the exhaust ports' areenclosedrbyI thej 03511718 '71, and the exhaust fluid permitted toescapel as described below to serve an additional useful purpose. Thebottom edges of theV casing 71 have but a Avery small clearance, about.002 of an inch, with the plate 3 asA at 73.

The padsupport member 1 is chamfered as at 74and 'the inner faceA of thecasing 71 is complementally charnfered alongthe lower edge as at 75. Thecasing71has asmall clearance with the ribs 18 vas at 76 and theVchamfered faces 74 and 75 likewise have but a very small clearance,about .0Q2 of anA inch. Obviously, the showing of these clearances isexaggerated for clearness.

Hence,v during operation the air from the exhaustports'q and 51fisprevented from escaping in everyvdirection by thecasing 71 exceptthrough the clearances 76f and 73 between Athe casing 71 and theribs 72and the slide member 1. This downward and outwardly directed blast ofair not only prevents the'access of dust to the sliding surfaces butalso drives out any dustvthat might collect adjacent the drivingsurfaceswhen the machine'is inoperative. A `further advantage of this exhaustlarrangement is that it provides a means for lubricating the motor andslide surfaces. For instance, theV airhose can be disconnected and oilshot intor the air line nozzle 58. The air hose again being connectedand the valve 60 opened, the oil is shot into the cylinder and outthrough. the exhaust ports 50 and 51 which completely atomizes l thesame. This atomized oil passes through the clearance 76 and lubricatesthe sliding surfaces between the, ribs 18 and the worksupport plate 1and rib 19.

lSincejthis, machine is also adapted for wet sanding, to Athis end the,casing 71 is provided with alongitudinalbore 80 which extends half, waythroughoutr'the length and connects with thev vertical jet producingbores 81. TheY longitudinal bore is connected to a suitable water line82 which is controlled by the pet-cock 83. Hence, when the pet-cock 83is opened, the vertical bores 81 direct the jets of water upon thesurface which is to be wet sanded.

In operation assuming that the check valve 62 has been opened as abovedescribed, the chamber 56 becomes a pressure chamber and the valve 29 isheld against the valve guide surface 28 thus permitting the operation ofthe polisher in any desired position, that is, right side up or up sidedown. The air is free to pass the valve through the clearance 57 betweenthe top of the valve and the top of the chamber 56 and between the sidesof the chamber 56 and the clearance 35 permitted by the narrowed centralportion 34 of the valve.-

As shown in Fig. 3, the piston is beginning to move to the right asindicated by the arrow. At this time the compressed air passes from thechamber 56 through the intake ports 31 and 39 into the left hand end o-fthe cylinder 14 as indicated by the arrows. At this time the exhaustport 50 is cut off by the valve 29. The right hand intake port nowserves as the exhaust port in that the air passes from the right handend of the cylinder as indicated by the arrows into the intake port 38through the connecting openings 46, 44, and 42 into the port 41 where itpasses upwardly into the chamber 32 and then downwardly through theopening 53 and outwardly through the exhaust opening 51 into theinterior of the enveloping casing 71 from which it escapes to theatmosphere through the clearances 7 6 and 73 as above described.

As soon as the stud 27 engages the right hand side of the opening 36 thevalve begins to mo-ve to shut 01T the intake port `39 on the left andeventually places the valve in the position shown in Fig. 4. At thistime the compressed air is being admitted through the intake ports 30and 38 to the right hand end of the cylinder 14 which in turn causes thepiston to move to the leftas indicated by the arrow. The left hand endof the cylinder is exhausting through the intake port 39, the connectingports 47, 45, 43 and 40, thence through the chamber 33 downwardlythrough the opening 52 and outwardly through the exhaust port 50 intothe casing 7l from which it is exhausted through the clearances 76 and73 between the casing 71 and the motor and work support slide as abovedescribed.

As shown in Figs. l0`to 13 the outer casing 71 is arranged to receivethe air feed line 102 and the water feed line 103. The slide valvehousing 104 is provided with the longitudinal opening 105 whichcommunicates with the air feed line 102 and with the longitudinalopening 106 which communicates with the water feed line 103. The opening105 communicates with the valve chamber 107 and is controlled by thevalve 108. The valve 108 has fixed on one end the cylindrical pushbutton 109 which slidably engages the opening 110 in the outer casing71. The valve 108 is yieldably held in closed position by the coilspring lll. The push button 109 is provided with the annular groove 112.

The casing 71 is provided with the transverse opening 113 which isarranged to receive the water control valve. The water control valve 114is of the push button elongated cylinder type, one end of which has ayieldable engagement with the coil spring 115. The valve 114 is providedwith an annular groove 116. The casing 71 is likewise` provided with alongitudinal bore 117 which communicates with the downwardly directedopenings 130 to deliver the water upon the surface which is beingworked. For the purpose of connecting the water line 106 with the waterfeed line 117 the valve 114 is provided with the U-shaped opening 118.

As shown in Fig. 10,-both the air and the water are turned oi. At thistime the push button 109 and spring lll are in extended position and thevalve 108 is held tightly against the valve seat 119 and the watercontrol push button 114 is pushed inwardly against the coil spring 115which is in collapsed position. At this time the annular groove 116 ofthe valve 114 is engaged by the cylindrical push button 109 as shown at120 (Fig. 11 and similarly in Fig. 10). Since the annular groove 11S hasa curvature corresponding to the curvature of the cylindrical pushbutton 109, the valve 114 is held in shut-off position and consequentlythe valve opening 118 is oir-set from both the feed line 106 and 117.

When it is desired to turn the air and water on the push button 109 ispushed in as shown in Figs. 12 and i3 against the tension of the spring111. As soon as the annular groove 112 coincides with the annular groove116 in the water control push button 114, the coil spring 115 forces thepush button 114 outwardly so that the opening 118 communicates with thewater feed lines 106 and 117. At this time, as shown in Figs. 12 and 13,the pin 114 engages the pin 109 in the annular groove 112 thus retainingthe valve 108 in open position. When it is desired to render the machineinoperative, the water valve 114 is pushed in which permits the spring111 .to again close the air valve 108, shut off the air, andsimultaneously lock the water control valve in the position shown inFigs. 10 and 11.

I claim:

1. A machine of the type described comprising in combination of acylinder, a piston having a pair of opposed recesses, a reciprocatorysupport for work performing means beneath the said cylinder and having aboss adapted to engage the said piston in one of the said recesses, aplug having a stud arranged to engage the said piston in the other ofsaid recesses, a reciprocating valve having a lost motion connectionwith the said stud, and means passing through the said boss and cylinderfor rigidly interconnecting the support, the cylinder, and the valveactuating stud.

2. A machine of the type described comprising in combination of acylinder, a piston having a pair of opposed polygonal similar recesses,a reciprocatory support for work performing means beneath the saidcylinder and having aboss adapted to snugly engage the said piston inone of the said recesses, a plug having a stud arranged to snugly engagethe said piston in the other of said recesses, a reciprocating valvehaving a lost motion connection with the said stud, and a threaded studpassing through the said boss in the cylinder and threadedly engagingthe said plug for rigidly interconnecting the support, the cylinder, andthe valve actuating plug.

3. In a pneumatically operated machine of the type described, acylinder, a piston for the cylinder, intake and exhaust ports, areciprocating valve for controlling the intake and exhaust ports, thesaid valve having an opening substantially centrally thereof, and areplaceable apertured insert for the said opening, and means carried bythe said piston having a lost motion connection with the said valveinsert whereby the valve is reciprocated to open and close the intakeand exhaust ports.

4. In a pneumatically operated machine of the type described, acylinder, a piston for the cylinder, a valve guide surface, areciprocating valve having a recess substantially centrally thereof, areplaceable apertured insert for the said Valve recess, and a studrigidly xed to the said piston and engaging the said valve insert in theaperture to actuate the valve, whereby the valve insert can be replacedby another valve insert having a different sized aperture to vary thestroke of the piston.

5. In a pneumatically operated machine of the type described having anair feed line and a Water feed line, a spring pressed valve forcontrolling the air feed line, a spring pressed valve for controllingthe Water feed line, one of said springs being compressed when the otheris expanded, each of said valves having a portion adapted to interlockwith a portion of the other whereby either valve serves as a stop forholding the other Valve in one of its predetermined positions.

6. In a pneumatically operated machine of the type described having anair feed line and a Water feed line, a spring pressed valve forcontrolling the air feed line, said valve having an annular groove, aspring pressed Valve for controlling the water feed line, said Valvealso having an annular groove, the said valves being positionedtransversely of each other whereby the one valve engages the other inthe annular groove to lock the same in a predetermined position.

'7. In a pneumatically operated machine of the type having an air feedline and a Water feed line, a spring pressed valve for controlling theair feed line, a spring pressed valve for controlling the Water feedline, the said Valves being positioned one across the other and eachhaving a notch, the spring of the one valve being com- .pressed when thespring of the other Valve is eX- panded whereby as the one valve isactuated to a predetermined position the compressed spring of the othervalve expands when the notches coincide thereby oifsetting the notchesand locking the said valve in the predetermined position.

JOHN G. PARTLOW.

